israel would also be more at odds with arab countries, such as egypt, which now has an islamist president. and a hardline stance would put a strain on israel's relations with united states and ordinations. >> netanyahu has cited iran's nuclear development as the biggest post-election challenge. how will he deal with that issue? >> his administration has not ruled out a preemptive strike if iran proceeds with its nuclear development. after exit polls projected his victory, netanyahu stressed again that israel must keep iran in check. >> translator: our biggest challenge remains, preventing iran from acquiring a nuclear weapon. >> but if israeli leaders resort to unilateral action in iran, they risk isolation and could further destabilize the region. whatever the composition of the incoming coalition, the focus wa continue to be on what prime minister netanyahu would say and do. >> all right, thanks, akira. nhk world's akira saheki in jerusalem. >>> japanese safety regulators say there's no evidence that battery that caught fire last week in a boeing 787 dreamliner was overcharged. investig